Sewing machine



Oct. 13, 1942.

N. V. CHRISTENSEN ETAL SEWING MACHINE Filed Sept. 8, 1938 6 Sheets-Sheetl INVENTORS:

Norman VL'IZTLSZ'UZSHL fiagold 1 122 Wscomiz; i auer ar ms W ,n'v'omvys.

George 747% Www A WI'I'NESSES? 7 "1/14, Aa

Oct. 13, 1942.- N. v. CHRISTENSEN ETAL 2,293,750

SEWING MAUI-ZINE Filed Sept. 8, 1938 6 Sheets-Swat WITNESSES:

Oct. 13, 1942. N. .v. CHRISTENSEN E'IIAL 2,293,750

SEWING MACHINE Filed Sept. 8, 1938 '6 Sheets-Sheet 3 L I J big 1 i i Q &

.f 2 m 3% E J i WITNESSES:

ATTORNEYS.

Geor qefiauerkflgar mist,

0% 1942- N. v. CHRISTENSEN ETAL 2,298,750

SEWING MACHINE Filed Sept. 8, 1938 6 Sheets-Sheet 5 INVENTORSi 7 Human;l L'h hsiensm, fibroid I [,e Mammy,

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Norman Vrchristensen, Chicago,rHarold.J.' Le

Vesconte, Western Springs, George Sauer, Berwynyand' Oscar Qulst,Chicago, 111.,- assignf on to Union'Special. Machine Company, 0111-cago, 111., a corporation of Illinois V Application September 8,1938,sesame. 228,888

' 13 Claims. (Cl. 1129155).

This invention relates to sewing machines; and

it has referencemore particularly to sewing machines of the-kinddisclosed in U. S. Patent No. 10,354, grantedtoS. C. Blodgett, 'onDecember 20, 1853, capable of making seams in Which spaced needle threadloops passing through the fabric from opposite sides at opposed angles,are inter- (Fig. i) of a horizontal shaft u journaled in fixed bearingsl2; l3, 14 within the hollow of the overhanging arm 3.

Slidable axially in inset bushings l and 16 on the-needle head 4 inparallel relation with the needle bar 5 is a presser bar I! with a shankmember I8 at its lower end whereto a presser locked with each otherat'points of intersection at the fabric surfaces, the seam having theappearance ,of an ordinary lockstitch seam when viewed from either sideof the fabric. 1 The chief aim'of our invention is to extend (theusefulness .of sewing machinesof the kind referred to with a view towardmaking possible their continuous operation at higher speeds forattainment of correspondingly greater 7 output from them;. insuringgreater'unifo'rmity in the seams produced by them; and enablingproduction of seams anywhere within the area of the fabric being sewedas well as'along itsedges.

One way in which theforegoing and other important advantages may bereadily realized in practice will appear from the following detaileddescription of the attached drawings, wherein Fig. I is a view, partlyin front elevation and partly in longitudinal section, of a sewingmachine conveniently embodying our invention.

foot 19 is pivotally connected, see Fig.'IV. The presser foot I! ismaintained in yielding engagement with the fabric F by a helical spring20 which surrounds thepresser b'ar l'| andwhich is in compressionbetween the bushing I5 and a fixed collar. 2! on said bar within thehollow of t the head 4. The bushing I5 is threaded into the Fig. IIshows the machine in top plan with the top covers removed from its frameto expose important parts within.

Fig. 111 is a fragmentary view showing the machine in bottom plan. Fig.IV is an end elevation of the machine. Fig. V is atransverse sectionalview taken as indicated by the arrows V--V in Figs. I and III.

Fig. VI is a fragmentary detail view looking as indicated by the arrowsVI--VI in Fig. IV.

Figs. VII XVIII are diagrammatic views showing the cycle of stitchformation with the coacting parts cccupyingdifierent successivepositions.-

As herein illustrated, our improved sewing machine has an elongatehorizontal rectangular work support I with a hollow standard 2 risingfrom one end thereof and supporting an integrally-formed longitudinaloverhanging arm 3, which, at its free end, terminates in a hollow needlehead 4. Confined to reciprocate axially in a plane inclined to thevertical is a needle bar 5 which is guided in aligned bearings 6 and Iset respectively into the top and bottom of the 1101- low needle head 4,and which, at its lower end,

carries a needle 8 adapted to penetrate fabric F' being sewed in themachine from above. The needle bar 5 is actuated, through a link 9, fromtop of the needle head '4 so that it may 'be adjusted axially toregulate the pressure of the spring 20.. The collar 2| has a lateralprojection Zia which extends outward through a vertical guide slot 22 inone side of the needle head 4 and so prevents rotation'of the presserbar II. By means of a verticallink 23, the collar H is coupled with oneend of a lever 24 fulcrumed near its'center on a screw stud 25projecting laterally from the overhanging arm 3, see Figs. I and II. Tothe opposite end of the lever 24 is connected a drop link rod 26 (Figs.I and IV) which may 'extend to a foot treadle or knee press (notillustrated) and which, upon being actuated, will cause the presser barI! to be lifted in opposition to the spring 20 to facilitateintroduction of the fabric F initially beneath the presser foot I9. Aspring shown at 21 in Figs. I and IV serves to maintain the lever 24normally in the position illustrated; and, a cam finger indicated at 28in Figs. IV and VI is provided as an auxiliary means for lifting thepresser bar l1 and at the same time locking it in raised position whendesired or required.

Cooperating with the needle 8 in the sewing is a needle 29 which isadapted to penetrate the fabric Fupwardly from below. As shown in Fig.IV, the needle 29 is secured to the upper end of a bar 30 which isoppositely inclined with respect to the bar 5 carrying the upper needle8, so that it intersects the path of said upper needle at a point P inthe top surface of the work support I in entering the fabric. The needlebar 30 is confined to endwise reciprocation in spaced guide bosses 3Ia,3Ib on a plate-like carrier 3| which is fulcrumed to oscillate about astud 32 secured in one of a series of holes 33 in an underslung bracket35 integrally formed with the work support I at the left hand endthereof. The lower,

needle bar 30 is connected by a link 33, with a balanced crank member 10at the left hand end one arm 31a of a bell crank 31 free on a rock shaft38 which is journaled at one end in the bracket 85, and at the other endin a bearing lug 39 pendant from thework support I. To the other arm 31bof the bell crank 3'! is connected the rod 48a of a strap 48 whichembraces an actuating eccentric 4I on a horizontal shaft 42 extendinglongitudinally of the machine beneath the work support I, see Fig. I. Atthe left hand end of the machine, the shaft 42 is journaled in anotherpendant bearing lug 43 on the work support I, and at the right hand endextends through bearings 45, 48 in a downward prolongation 41 of thestandard 2, below the work support I, said prolongation being closed atthe bottom by a removable cover plate 48 to serve as a sump which iskept filled with lubricating oil to the level conventionally indicatedin Fig. I.

The fabric F is advanced crosswise of the work support I by a toothedfour-motion feed dog 58 (Fig. V) which operates upwardly through anopening I in the throat plate 52 of the machine. As shown in Fig. V, thefeed dog 58 overreaches the shaft 42 and has its shank secured by ascrew 53 to a feed bar 55. At its rear end, the feed bar 55 is pivotallyconnected to the top of a vertical arm 58 on a rock shaft 51 at the sideof the machine opposite that occupied by the rock shaft 38. The rockshaft 5'! is journaled at one end in the bracket 35, and at spacedintervals in pendant lugs 58, 59 of the bed plate I, and to it isclamped a slotted arcuate arm 8|. By means of a bolt 82 adjustable alongthe slot of the arm 6|, one end of a link 83 is connected to said arm, I

the other end of said link being connected at 85 to the strap 56 ofanother eccentric 81 on the shaft 42, the pivot 85 being supported atthe swing end of a lazy bar 68 swingable on a rod 89 whereof theopposite ends are fixed in the hearing lugs 58, 59. By the action of theeccentric 81, the shaft 5'! is oscillated continuously with resultantimpartation of feeding movements to the feed dog 58. The throw of thefeed dog 58 may be varied by adjusting the bolt 82 along the arm GIwithout attendant change in the timing of the feed movements since thepivotal connection 85 between the link 63 and the eccentric strap 88 isrestricted to a fixed arcuate path by has its the lazy bar 88. Thearcuate arm 6| center of curvature in the axis of the pivot pin 65 whichconstitutes the common connection between the eccentric strap 88 and thelinks 63 and 68 at the time when the feed dog 58 is in its forwardposition, i. e., in its extreme position to the right in Fig. V. Thenecessary lift movements are induced in the feed dog 58 from stillanother eccentric I8 on the shaft 42, said eccentric being embraced by astrap II which is pivotally connected at its lower end at I2 to anunderreaching arm 55a integrally formed with the feed bar 55. By thearrangement just described, the feed dog 58 is actuated in a well knownmanner to positively advance the fabric step by step crosswise of thework support I while opposed by the reacting pressure of the presserfoot I9 from above. For the purpose of moving the lower needle 29laterally in synchronism with the feed movements of the feed dogimmediately upon having entered the fabric, in accordance with ourinvention, we have provided mechanism for imparting oscillatorymovements to the carrier 3 I. As shown, this mechanism includes a linkI3 whereof the lower end is connected at I4 to the carrier 3i, and theupper end at I5 to an arm 16 clamped to the rock shaft 38 previouslyreferred to. Similarly secured to the rock shaft 38 75 is another arm IIwhich at I8 is connected to the lower end of the strap rod 19 of anothereccentric 88 (Fig. III) on the shaft 42.

The shafts II and 42 are connected for rotation in unison by atransmission 8| within the hollow of the standard 2. This transmissionincludes spur gears 82. 83 respectively on the shafts II, 42, and anintermediate intermeshing idler gear 85 which is free to rotate on ashaft 88 secured in bosses 81, 88 at opposite sides of the standard 2.As shown, the pinions 82, 83 comprise opposingly arranged half sections82a, 82b, and 83a, 83b respectively which are rotatively adjustablerelatively on the shafts II and 42. for wear take up. The transmissionBI per se, constitutes the subject matter of a co-pending applicationNo. 211,712, filed on June 4, 1938, by George Sauer, one of the presentapplicants. While either of the shafts II, 42 may be utilized as thedrive shaft of the machine, we preferably employ the lower shaft 42 forthat purpose, and to this end have provided it with a combined handwheel and pulley 89. For convenience of operating the machine manuallyin making adjustments we have secured a hand wheel 98 to the upper shaftII, as shown in Fig. I.

Pivotally connected at 9| to a fixed bracket 92 beneath the work supportI is a finger 93 which is adapted to engage and temporarily hold thethread loops thrown out by the upper needle 8 as the latter begins torecede upwardly after having penetrated the fabric F, see Fig. IV, sothat the lower needle 29 may enter said loops before it has penetratedthe fabric. As shown, the finger 93 has a depending arm 95, which, by

.means of a link 96 is coupled with an arm 91 on ,is coupled to anotherarm I8I secured to said shaft 98, see Figs. III and V. Pivoted at I82 toa lateral projection I03 on the shank member I8 to which the presserfoot I9 is pivoted is a finger I 85 which is adapted to engage thethread loop thrown out by the lower needle 29 as the latter begins torecede downward, after having penetrated the fabric F, so that the upperneedle 8 may enter said loops at the initiation of its down strokes. Thearm I88 of the finger I85 is coupled, by means of a horizontal link rodI81 with the lower end of an arm I88 clamped to one end of a rock shaftI89, which, as shown in Fig. VI, is journaled in a lug projection I I8at the rear side of the needle head 4. To the opposite end of the rockshaft I89 inward of the lug H8 is secured an upwardly extending arm III,which, at the top, has a pivotal connection at I I2 with the strap rodII3 of the eccentric II4 on the upper needle actuating shaft IIall asshown in Fig.

laterally to the left concurrently with its axial advancement upwardlyas the feed dog, begins feeding the fabric in the same direction. At thesame time the finger 93 is receding to release the thread loop of theupper needle 8 and the linger I is advancing in preparation for engagingthe thread loop (not shown) of said lower needle. The several partscontinue. in these movements through the positions of Fig. IX to thepositions of Fig. X where the lower needle 49 has fully penetrated thefabric F and reached its highest position. In Fig. XI, the lower needle29 has just begun to recede downward axially while still continuing inits leftward movement synchronously with advance of the fabric F. InFig. XII, the finger I05 has entered the thread loop of the recedinglower needle 29. In Fig.

XIII, the lower needle 29 has completed its lefttoward its activeposition. The parts thereafter continue in these movements through thepositions of Fig. XV to the positions of Fig. XVI wherein the upperneedle 8 has completed its downward stroke. In Fig. XVII the upperneedle 8 has begun its upward stroke and the finger 93 is about toengage the thread loop of said needle. In Fig. XVIII, the upper needle 8is about to leave the fabric and the finger 93 is holding the upperneedle thread loop in readiness for the lower needle 29 to pass throughit in the manner shown in Fig. VII.

Repetitions of the above cycle will obviously result in a seam like thatshown in the Blodgett patent hereinbefore referred to. It will moreoverbe evident from theforegoing that our improved sewing machine issusceptible of continuous operation at speeds comparable with that ofordinary single needle sewing machines, and mrreover that it is notlimited to seaming solely along the edges of the fabric as is the casewith the machine of the Blodgett patent supra.

The length of stitch may be varied by selection between the holes 33 inthe bracket 35 for placement of the stud 32 on which the carrier, 3| forthe lower needle 29 oscillates, since said holes are arranged in an arcstruck from 'he point P (Figs. IV and VII) at the surface If the worksupport of the machine in which the axial fabric-penetrating paths ofthe needles 8 and 29 intersect. Thus, when the stud 32 is shifted to theright in Fig. IV, the angle ztween the link 13 and the arm IE will bedecreased with attendant decrease in the amount of rocking movementimparted to the carrier 3|. Similarly, shifting the fulcrum stud 32leftward in Fig. IV will be attended by increase inthe angle between thelink 13 and the arm 16, a d hence in the rocking movement of the'ditions of adjustment of the fulcrum 32 start substantially at the pointP and the increases or' decreases in movement resulting from suchadJustments will be at the end of the feed stroke of said needle. In theevent that extreme accuracy is required to insure intersection of thelower needle 29 with the upper needle 8 exactly at the point P, the arm16 may be adjusted circumferentially of the rock shaft 38 to thenecessary extent after transposal of the fulcrum pin32 for the guidemember 3|, in a manner which will be obvious from Fig. IV.

Having thus described our invention, we claim:

1. A sewing machine comprising a work support; feeding means forengaging fabric and intermittently advancing it on the work support; aneedle adaptedto penetrate fabric on the work support from above; meansfor actuating said needle; a second needle adapted to penetrate thefabric from below; a pivoted carrier in which the second needle isguided for axial movement; means for actuating the second needle inalternation with the first needle; and means for oscillating the carrierwhile the second needle is engaged in the fabric, to move said needlelatorally in synchronism with the fabric advancing movements of thefeeding means.

2. A sewing machine comprisinga work sup-' port; feeding means forengaging fabric and I intermittently advancing it on the work support; aneedle adapted to penetrate fabric on the work support from above; meansfor actuating said needle; a second needle adapted to penetrate thefabric from below; a pivoted carrier in which the second needle isguided'for endwise reciprocation; a shaft journaled beneath theworksupport; means deriving movement from said shaft for reciprocatingthe second needle endwise as aforesaid in alternation with the movementsof the upper needle; and means also deriving movement from the shaft foractuating the carrier to move the second needle laterally while it isengaged in the fabric synchronously with the fabric advancing movementsof the feeding means.

3. A sewing machine comprising a work support; feeding means forengaging the fabric and intermittently advancing it on the work support;a needle adapted to penetrate the fabric from above; a shaft above thework support from which said needle is actuated; a second needle adaptedto penetrate the fabric from beneath;v

a shaft below the work support from which the second needle is actuatedin alternation with the first needle; meansalso actuated from the lowershaft for moving the second needle lat erally, while engaged in thefabric, in synchronism with the fabric advancing movements of thefeeding means; means below the work support actuated from the lowershaft for spreading and temporarily holding the thread loop of the firstneedle to enable entry thereinto of the second needle; means above thework support acfabric and intermittently advancing it on the worksupport; a needle for penetrating the fabric from above; means foractuating the needle; a

said point. Accordingly the lateral feed move-j ment of the lower needle29 will under all con second needle for penetrating the fabric frombeneath; means for actuating the second needle; a pivoted carrier belowthe work support in which the second needle is guided for reciprocationin an inclined path intersecting that of the first needle in a point atthe surface of the work support; mechanism for oscillating the carrierto move the second needle laterally while in the fabric, in synchronismwith the fabric advancing movements of the feeding means, said mechanismincluding a rock shaft below the work support, a lateral arm on saidrock shaft and a vertical link connecting said arm with said carrier;means whereby the pivot for the carrier can be adjusted along an arcstruck from the point of intersection of the needle paths, to increaseor decrease the lateral movements of the second needle compensativelywith the adjustments of the feeding means.

5. A sewing machine comprising a work support; a feedingelement forintermittently advancing the fabric on the work support; means foractuating the feeding element; a pair of needles for penetrating thework from opposite sides; guides respectively determining passage of theneedles through a point of intersection at the level of the worksupport; means for actuating the needles; means for actuating one of theguides so that the corresponding needle is shifted laterally relative tosaid point while in the fabric synchronously with the advance shifts ofthe fabric by the feeding means; and means for adjusting the feedactuating means and the guide of the laterally shiftable needlecompensatively without entailing any substantial change in the positionof the intersection point for the purpose of stitch length variationrelative to said point.-

6. A sewing machine comprising a work support; a feeding element forengaging fabric and intermittently advancing it on the work support;means for actuating said feeding element; a pair of needles adapted toalternately penetrate the fabric from opposite sides respectively; meansfor guiding the needles to reciprocate axially along angular paths whichintersect in a point at the surface of the work support; means foractuating the needles; means for moving the guide for one of the needlesso that the path of said needle is shifted laterally, relative to theaforesaid point after the needle has entered the fabric, in synchronismwith the advance shifts of the fabric by the feeding element; and meansfor adjusting the feed actuating means and the guide of the laterallyshiftable needle compensatively to effect stitch length variationsubstantiallywithout attendant change in the point of intersection ofthe needle paths.

'7. A sewing machine comprising a work support; a feeding element forengaging fabric and intermittently advancing it on the work support;means for actuating said feeding element; a pair of needles adapted toalternately penetrate the fabric from opposite sides respectively;guides respectively for said needles determining intersection of thepaths of the latter in a fixed point at the level of the work support;means for actuating the needles; actuating means for moving one of theguides to laterally shift the path of the corresponding needle while inthe fabric synchronously with the advance shifts of the fabric by thefeeding element; means at one side of the work support for spreading andtemporarily holding the thread loop of one needle to enable entrythereinto of the other needle after the latter has penetrated thefabric; means at the opposite side of the work support for spreading andtemporarily holding the thread loop of said other needle to enable entrythereinto of the first mentioned needle after the latter has penetratedthe fabric; and means for adjusting the feed actuating means and theguide of the laterally shiftable needle compensatively to effect stitchlength variation substantially without attendant change in the point ofintersection of the needle paths.

8.'A sewing machine comprising a work su'pport; a feeding element forengaging fabric and intermittently advancing it on the work support;means for actuating said feeding element; a pair of needles adapted toalternately penetrate the fabric from opposite sides respectively; meansfor actuating the needles; guides respectively for the needles todetermine intersection of the paths of the latter in a point at thelevel of the work support; means for moving one of the guides tolaterally shift the path of the corresponding needle after it hasentered the fabric, in synchronism with the advance shifts of the fabricby the feeding element; means at one side of the work support forspreading and temporarily holding the thread loop of one needle toenable entry thereinto of the other needle after the latter haspenetrated the fabric; means at the opposite side of the work supportfor spreading and temporarily holding the thread loop of said otherneedle to enable entry thereinto of the first mentioned needle after thelatter has penetrated the fabric; and means for adjusting the feedactuating means and the guide of the laterally shiftable needlecompensatively to effect stitch length variation substantially withoutattendant change in the point of intersection of the needle paths.

9. A sewing machine comprising a horizontal work support; a feedingelement for engaging fabric and intermittently advancing it on the worksupport; means for actuating the feeding element; a pair of opposingupper and lower needles adapted to alternately penetrate the fabricrespectively from opposite sides; means for actuating the needles;guides for determining intersection of the paths of the needles in apoint at the level of the work support; means below the work support forspreading and temporarily holding the loop of the upper needle after ithas penetrated the fabric to permit entry of the lower needle; meansabove the work support for similarly spreading and temporarily holdingthe loop of the lower needle after it has penetrated the fabric topermit entry of the upper needle; actuating means operative to move theguide of one of the needles while engaged in the fabric to laterallyshift its path synchronously with each fabric-advancing shift of thefeeding element; and means for adjusting the actuating feed means andthe guide of the laterally shiftable needle commnsatively to effectstitch length variation substantially without attendant change in thepoint of intersection of the needle paths.

10. A sewing machine comprising a horizontal work support; a shaftjournaled above said work sup-port; another shaft journaled below thework support; a feeding element for engaging fabric and intermittentlyadvancing it on the Work support; means for actuating the feedingelement; a

needle adapted to penetrate the fabric from above; means for guiding theneedle to pass through the work support; means whereby said needle isactuated from the upper shaft; a second needle adapted to penetrate thefabric from below; means whereby the second needle is actuated from thelower shaft in alternation with the first needle; means for guiding thesecond needle in a path which intersects the path of the first needle atthe level of the work support; means actuated from the lower shaftwhereby the guide means for the second needle is moved to laterallyshift the path of the latter while engaged in the fabric in synchronismwith each fabric-advancing shift of the feeding means; and means foradjust;-

ing the feed actuating means and the guide means of the laterallyshiftable needle compensatively to effect stitch length variationsubstantially without attendant change in the-point of intersection ofthe needle paths.

11; A sewing machine comprising a work support; a needle; means forreciprocating the needle endwise; means for guiding the needle to passthrough the work support always at the same point during its workpiercing stroke; means tov cooperate with the needle in stitch formationat said point; means for moving the guide to shift the needle laterallyafter having penetrated the work to intermittently advance the work onthe work support; and means for adjusting the guide at the same pointduring its work penetrating stroke; means for moving the guide to shiftthe needle laterally while in the fabric'in synchronism with the feedingmovement of the feeding element; means to cooperate with the needle institch formation at said point; means for adjusting the guidefor thepurpose of increasing or decreasing the lateral throwof the needle withrespect to the point aforesaid in which the needle passes through thework support, to vary the stitch length; and means for adjusting thefeed reciprocating means compensatively to corresp'ondingly increase ordecrease the throw of the feed dog relative to a fixed point ofstarting.

13. A sewing machine comprising a work support; a'needle; means forreciprocating the needle endwise; a four motion feed dog; means foractuating the feed dog to intermittently advance fabric on the worksupport; means for guiding the needle to pass through the work supportalways at the same point during its work penetrating stroke; means formoving the guide to shift the needle laterally while in the fabric insynchronism with the feeding stroke of the feed dog; means to cooperatewith the needle in stitch formation at said point; means for adjustingthe guide for the purpose of increasing or decreasing the lateral throwof the needle with respect to the point aforesaid in which the needlepasses through the work support to vary the stitch length; and means foradjusting the feed actuating means compansatively to correspondinglyincrease or decrease the stroke of the feed dog relative to a fixedpoint of starting.

NORMAN V. CHRISTENSEN.

; HAROLD J. LE VESCQNTE.

GEORGE SAUER. OSCAR QUIST.

